Lifting-jack



UNITED STATES PATENT OFFICE.

JAMES THORP, OF FORT GRIFFIN, TEXAS.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 302,056, dated July 15, 1884.

Application filed May 31, 1884.

Fort Griffin, in the county of Shackelford and State of Texas, have invented certain new and useful Improvements in Lifting-Jacks; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in lifti11g-jacks, the object of the samebeing to provide a device of this character which shall be simple and economical in construction and durable and efficient in use; and with these ends in view my invention consists in certain featu'resof construction and combinations of parts, as will be more. fully described, and pointed out in the claims.

In the drawings, Figure 1 is a view in side elevation of my improvement in its raised adjustment. Fig. 2 is a view of the same in its lowered adjustment.

A represents the main body or standard of a lifting-jack,centrally provided with the ver tically open slot 13, adapted to receive the sliding section 0, the lower end or tongue, D, of which is held against lateral displacement in the slot B by means of the metallic band E, which is preferablyloeated at the open end of the slot B, and serves as a brace to the sides of the'jack, in addition to guiding the section 0. The upper portion of 'the lifting-section G is provided with the shoulders F and Gr, by means of which the jack is allowed a wider range of adjustment beneath the'axles of vehicles. The lower portion of the elevating- .section 0 is cut away, as shown, thus forming a recess, H. At the upper part'of the said recess is pivoted a link-arm, I, preferably made of metal, and to the lower end of which is pivotally secured the short end of a lever, J, the

said lever J being pivoted to the side K of the standard A. The side Kis provided with suitable recesses, L, by means of which the lower end of the link-arm I is permitted to move away from the slot, as will be found necessary when it is'desired to elevate and lower the section 0.

(No model.)

It will be seen that when the sliding section is elevated and a weight brought to bear upon the same the link-arm I will be caused to occupy an oblique position and the lever J thrown past the center with respect to the link, thus causing the downward pressure of the sliding section with the weight thereon to lock the lever, and thereby the sliding section in the required position. A pin, M, set in the side of the standard, forms a stop to prevent the handle of the lever from swinging too far past the center; or the upper wall of the upper recess, L, may serve as a stop to the linkarm and prevent the lever from being swung too far past the center.

Having fully described my invention, What I claim as new, and desire to secure by Letters Patent, is-

1; In a liftingjack, the'combination, with, a standard provided with an elongated open slot and a movable section adapted to slide within the slot, of an operating-lever pivoted to the standard at the side of the slot, and a link pivotally secured to the sliding section and lever, whereby the lever is thrown past the center and .the sliding section thereby locked in an elevated position, substantially as set forth. r

2. In a lifting-jack, the combination, with a slotted stan dard' provided with recessed portions at one side of the slot and an operatinglever pivoted to'the' standard between the recessed portions, of asliding section adapted to move vertically Within the slot, the sliding section having a recessed lower portion, and a link connecting the sliding section and operating-lever, said link being adapted 'to swing into the recess in the standard as the sliding 

